1. Field of the Invention
This invention relates to a system and apparatus for the control of overflow from liquid storage tanks, particularly petroleum product storage tanks, to prevent the overflow from contaminating the environment.
2. Description of the Prior Art
Overflow control of liquid storage tanks has been a problem with various liquids, and particularly with petroleum products. Storage tanks are subject to random product releases caused by overfilling and by product expansion. The overflow releases emanate from the fill pipe or from the emergency venting device, or both. If no overflow control is provided, the liquid product leaves the tank and ultimately enters the environment around the tank. Such action contaminates soil and water resources converting them to hazardous material subject to costly handling and clean up processes.
In the past, various proposals have been utilized for controlling overflow. Fill pipe overflow containers have been proposed with various funnel-like arrangements to collect the overflow and guide it to a container. Many liquid storage tanks are situated within box-like dikes that serve as a safety arrangement to collect any overflow that may leave the tank and prevent it from reaching the soil around the tank. The prior art does not provide for a single weatherproof integrated system capable of handling fill and vent releases concurrently in a staged manner. The present invention does provide such a system.